The change by the social media giant, which will be implemented over the coming months, will lead to more wordy tweets and is aimed at giving its users greater freedom to express themselves.

It is yet another attempt by the San Francisco company to make its messaging service easier to use and to attract new users.

Twitter has struggled for years to find a cure for slow user growth. The number of people using Twitter is less than one fifth of those actively using its rival, Facebook.

Last year, it launched a channel called Moments that brings together hot topics in one place. And earlier this year, it tweaked its timeline to show tweets that users may have missed while they were away.

Twitter did not, as many had speculated in recent months, abolish its character limit.

A person's Twitter handle, which starts with the "@" symbol, will also not count against character limits. And people will be able to retweet and quote their own tweets.

In another change, any new tweet beginning with an @name will be seen by all followers. Previously, a tweet that started with a person's handle did not become part of their feed.

Twitter has tried to keep all users happy, those for and against relaxing character limits, by sticking to the current count while allowing more freedom to express thoughts, or rants, through images and other media.

Above all, Twitter hopes that the changes will re-ignite user growth.

The company, which recently celebrated its 10th birthday, currently has around 310 million users, which is even fewer than the professional networking service LinkedIn.

Facebook has 1.65 billion users. Even though many people are familiar with Twitter, the company has been unable to convert them to active users. Twitter remains hard to understand for many, with its own language of hashtags and symbols.

Twitter brought back co-founder Jack Dorsey late last year.

But company shares continue to haemorrhage, falling 40% this year. Shares on Tuesday fell by 4%.